[libvirt] [PATCHv2] Macro for testing the version you are compiling with

[Eric Blake]

On 11/13/2013 11:02 AM, Doug Goldstein wrote:
> Added a macro similar to the GLib's GLIB_CHECK_VERSION so that one can
> simplydo something like:

s/simplydo/simply do/

> 
>  #if LIBVIRT_CHECK_VERSION(1,1,3)
>    /* Call function here that appeared in 1.1.3 and newer */
>    virSomeNewFunction();
>  #endif
> ---
>  include/libvirt/libvirt.h.in | 14 ++++++++++++++
>  1 file changed, 14 insertions(+)

Closer.

> 
> diff --git a/include/libvirt/libvirt.h.in b/include/libvirt/libvirt.h.in
> index 80b2d78..65f98c6 100644
> --- a/include/libvirt/libvirt.h.in
> +++ b/include/libvirt/libvirt.h.in
> @@ -1466,6 +1466,20 @@ VIR_EXPORT_VAR virConnectAuthPtr virConnectAuthPtrDefault;
>  
>  #define LIBVIR_VERSION_NUMBER @LIBVIRT_VERSION_NUMBER@
>  
> +/**
> + * LIBVIRT_CHECK_VERSION:

Should we document @major, @minor, @micro here, so the doc comments are
more complete?

> + *
> + * Macro for developers to easily check what version of the library
> + * their code is compiling against.
> + * e.g.
> + * #if LIBVIR_CHECK_VERSION(1,1,3)

Mismatch between LIBVIRT_ vs. LIBVIR_.  Given that we already expose
LIBVIR_VERSION_NUMBER, I think the LIBVIR_ prefix is preferred for the
public interface, and that this example is correct...

> + *   // some code that only works in 1.1.3 and newer
> + * #endif

Indent the #if and #endif, so that the generated html page represents
this as a three-line code box.

> + */
> +#define LIBVIRT_CHECK_VERSION(major,minor,micro) \

...while the define name has an extra T.

Space after comma.

> +    ((((major) * 1000000) + ((minor) * 1000) + (micro)) <= \

This isn't lisp :)  The following is equivalent, with fewer ():

((major) * 1000000 + (minor) * 1000 + (micro) <= LIBVIR_VERSION_NUMBER)

> +     LIBVIR_VERSION_NUMBER)
> +
>  int                     virGetVersion           (unsigned long *libVer,
>                                                   const char *type,
>                                                   unsigned long *typeVer);
> 

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org

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